skeletonfb.c

来自「Linux环境下视频显示卡设备的驱动程序源代码」· C语言 代码 · 共 1,037 行 · 第 1/3 页

     *  and higher than that, true/directcolor.  This is incorrect, one needs
     *  to look at the fix->visual.
     *
     *  Another common mistake is using bits_per_pixel to calculate the color
     *  depth.  The bits_per_pixel field does not directly translate to color
     *  depth. You have to compute for the color depth (using the color
     *  bitfields) and fix->visual as seen above.
     */

    /*
     * This is the point where the color is converted to something that
     * is acceptable by the hardware.
     */
#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
    red = CNVT_TOHW(red, info->var.red.length);
    green = CNVT_TOHW(green, info->var.green.length);
    blue = CNVT_TOHW(blue, info->var.blue.length);
    transp = CNVT_TOHW(transp, info->var.transp.length);
#undef CNVT_TOHW
    /*
     * This is the point where the function feeds the color to the hardware
     * palette after converting the colors to something acceptable by
     * the hardware. Note, only FB_VISUAL_DIRECTCOLOR and
     * FB_VISUAL_PSEUDOCOLOR visuals need to write to the hardware palette.
     * If you have code that writes to the hardware CLUT, and it's not
     * any of the above visuals, then you are doing something wrong.
     */
    if (info->fix.visual == FB_VISUAL_DIRECTCOLOR ||
	info->fix.visual == FB_VISUAL_TRUECOLOR)
	    write_{red|green|blue|transp}_to_clut();

    /* This is the point were you need to fill up the contents of
     * info->pseudo_palette. This structure is used _only_ by fbcon, thus
     * it only contains 16 entries to match the number of colors supported
     * by the console. The pseudo_palette is used only if the visual is
     * in directcolor or truecolor mode.  With other visuals, the
     * pseudo_palette is not used. (This might change in the future.)
     *
     * The contents of the pseudo_palette is in raw pixel format.  Ie, each
     * entry can be written directly to the framebuffer without any conversion.
     * The pseudo_palette is (void *).  However, if using the generic
     * drawing functions (cfb_imageblit, cfb_fillrect), the pseudo_palette
     * must be casted to (u32 *) _regardless_ of the bits per pixel. If the
     * driver is using its own drawing functions, then it can use whatever
     * size it wants.
     */
    if (info->fix.visual == FB_VISUAL_TRUECOLOR ||
	info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
	    u32 v;

	    if (regno >= 16)
		    return -EINVAL;

	    v = (red << info->var.red.offset) |
		    (green << info->var.green.offset) |
		    (blue << info->var.blue.offset) |
		    (transp << info->var.transp.offset);

	    ((u32*)(info->pseudo_palette))[regno] = v;
    }

    /* ... */
    return 0;
}

/**
 *      xxxfb_pan_display - NOT a required function. Pans the display.
 *      @var: frame buffer variable screen structure
 *      @info: frame buffer structure that represents a single frame buffer
 *
 *	Pan (or wrap, depending on the `vmode' field) the display using the
 *  	`xoffset' and `yoffset' fields of the `var' structure.
 *  	If the values don't fit, return -EINVAL.
 *
 *      Returns negative errno on error, or zero on success.
 */
static int xxxfb_pan_display(struct fb_var_screeninfo *var,
			     struct fb_info *info)
{
    /*
     * If your hardware does not support panning, _do_ _not_ implement this
     * function. Creating a dummy function will just confuse user apps.
     */

    /*
     * Note that even if this function is fully functional, a setting of
     * 0 in both xpanstep and ypanstep means that this function will never
     * get called.
     */

    /* ... */
    return 0;
}

/**
 *      xxxfb_blank - NOT a required function. Blanks the display.
 *      @blank_mode: the blank mode we want. 
 *      @info: frame buffer structure that represents a single frame buffer
 *
 *      Blank the screen if blank_mode != FB_BLANK_UNBLANK, else unblank.
 *      Return 0 if blanking succeeded, != 0 if un-/blanking failed due to
 *      e.g. a video mode which doesn't support it.
 *
 *      Implements VESA suspend and powerdown modes on hardware that supports
 *      disabling hsync/vsync:
 *
 *      FB_BLANK_NORMAL = display is blanked, syncs are on.
 *      FB_BLANK_HSYNC_SUSPEND = hsync off
 *      FB_BLANK_VSYNC_SUSPEND = vsync off
 *      FB_BLANK_POWERDOWN =  hsync and vsync off
 *
 *      If implementing this function, at least support FB_BLANK_UNBLANK.
 *      Return !0 for any modes that are unimplemented.
 *
 */
static int xxxfb_blank(int blank_mode, struct fb_info *info)
{
    /* ... */
    return 0;
}

/* ------------ Accelerated Functions --------------------- */

/*
 * We provide our own functions if we have hardware acceleration
 * or non packed pixel format layouts. If we have no hardware 
 * acceleration, we can use a generic unaccelerated function. If using
 * a pack pixel format just use the functions in cfb_*.c. Each file 
 * has one of the three different accel functions we support.
 */

/**
 *      xxxfb_fillrect - REQUIRED function. Can use generic routines if 
 *		 	 non acclerated hardware and packed pixel based.
 *			 Draws a rectangle on the screen.		
 *
 *      @info: frame buffer structure that represents a single frame buffer
 *	@region: The structure representing the rectangular region we 
 *		 wish to draw to.
 *
 *	This drawing operation places/removes a retangle on the screen 
 *	depending on the rastering operation with the value of color which
 *	is in the current color depth format.
 */
void xxxfb_fillrect(struct fb_info *p, const struct fb_fillrect *region)
{
/*	Meaning of struct fb_fillrect
 *
 *	@dx: The x and y corrdinates of the upper left hand corner of the 
 *	@dy: area we want to draw to. 
 *	@width: How wide the rectangle is we want to draw.
 *	@height: How tall the rectangle is we want to draw.
 *	@color:	The color to fill in the rectangle with. 
 *	@rop: The raster operation. We can draw the rectangle with a COPY
 *	      of XOR which provides erasing effect. 
 */
}

/**
 *      xxxfb_copyarea - REQUIRED function. Can use generic routines if
 *                       non acclerated hardware and packed pixel based.
 *                       Copies one area of the screen to another area.
 *
 *      @info: frame buffer structure that represents a single frame buffer
 *      @area: Structure providing the data to copy the framebuffer contents
 *	       from one region to another.
 *
 *      This drawing operation copies a rectangular area from one area of the
 *	screen to another area.
 */
void xxxfb_copyarea(struct fb_info *p, const struct fb_copyarea *area) 
{
/*
 *      @dx: The x and y coordinates of the upper left hand corner of the
 *	@dy: destination area on the screen.
 *      @width: How wide the rectangle is we want to copy.
 *      @height: How tall the rectangle is we want to copy.
 *      @sx: The x and y coordinates of the upper left hand corner of the
 *      @sy: source area on the screen.
 */
}


/**
 *      xxxfb_imageblit - REQUIRED function. Can use generic routines if
 *                        non acclerated hardware and packed pixel based.
 *                        Copies a image from system memory to the screen. 
 *
 *      @info: frame buffer structure that represents a single frame buffer
 *	@image:	structure defining the image.
 *
 *      This drawing operation draws a image on the screen. It can be a 
 *	mono image (needed for font handling) or a color image (needed for
 *	tux). 
 */
void xxxfb_imageblit(struct fb_info *p, const struct fb_image *image) 
{
/*
 *      @dx: The x and y coordinates of the upper left hand corner of the
 *	@dy: destination area to place the image on the screen.
 *      @width: How wide the image is we want to copy.
 *      @height: How tall the image is we want to copy.
 *      @fg_color: For mono bitmap images this is color data for     
 *      @bg_color: the foreground and background of the image to
 *		   write directly to the frmaebuffer.
 *	@depth:	How many bits represent a single pixel for this image.
 *	@data: The actual data used to construct the image on the display.
 *	@cmap: The colormap used for color images.   
 */

/*
 * The generic function, cfb_imageblit, expects that the bitmap scanlines are
 * padded to the next byte.  Most hardware accelerators may require padding to
 * the next u16 or the next u32.  If that is the case, the driver can specify
 * this by setting info->pixmap.scan_align = 2 or 4.  See a more
 * comprehensive description of the pixmap below.
 */
}

/**
 *	xxxfb_cursor - 	OPTIONAL. If your hardware lacks support
 *			for a cursor, leave this field NULL.
 *
 *      @info: frame buffer structure that represents a single frame buffer
 *	@cursor: structure defining the cursor to draw.
 *
 *      This operation is used to set or alter the properities of the
 *	cursor.
 *
 *	Returns negative errno on error, or zero on success.
 */
int xxxfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
{
/*
 *      @set: 	Which fields we are altering in struct fb_cursor 
 *	@enable: Disable or enable the cursor 
 *      @rop: 	The bit operation we want to do. 
 *      @mask:  This is the cursor mask bitmap. 
 *      @dest:  A image of the area we are going to display the cursor.
 *		Used internally by the driver.	 
 *      @hot:	The hot spot. 
 *	@image:	The actual data for the cursor image.
 *
 *      NOTES ON FLAGS (cursor->set):
 *
 *      FB_CUR_SETIMAGE - the cursor image has changed (cursor->image.data)
 *      FB_CUR_SETPOS   - the cursor position has changed (cursor->image.dx|dy)
 *      FB_CUR_SETHOT   - the cursor hot spot has changed (cursor->hot.dx|dy)
 *      FB_CUR_SETCMAP  - the cursor colors has changed (cursor->fg_color|bg_color)
 *      FB_CUR_SETSHAPE - the cursor bitmask has changed (cursor->mask)
 *      FB_CUR_SETSIZE  - the cursor size has changed (cursor->width|height)
 *      FB_CUR_SETALL   - everything has changed
 *
 *      NOTES ON ROPs (cursor->rop, Raster Operation)
 *
 *      ROP_XOR         - cursor->image.data XOR cursor->mask
 *      ROP_COPY        - curosr->image.data AND cursor->mask
 *
 *      OTHER NOTES:
 *
 *      - fbcon only supports a 2-color cursor (cursor->image.depth = 1)
 *      - The fb_cursor structure, @cursor, _will_ always contain valid
 *        fields, whether any particular bitfields in cursor->set is set
 *        or not.
 */
}

/**
 *	xxxfb_rotate -  NOT a required function. If your hardware
 *			supports rotation the whole screen then 
 *			you would provide a hook for this. 
 *
 *      @info: frame buffer structure that represents a single frame buffer
 *	@angle: The angle we rotate the screen.   
 *
 *      This operation is used to set or alter the properities of the
 *	cursor.
 */
void xxxfb_rotate(struct fb_info *info, int angle)
{
/* Will be deprecated */
}

/**
 *	xxxfb_sync - NOT a required function. Normally the accel engine 
 *		     for a graphics card take a specific amount of time.
 *		     Often we have to wait for the accelerator to finish
 *		     its operation before we can write to the framebuffer
 *		     so we can have consistent display output. 
 *
 *      @info: frame buffer structure that represents a single frame buffer
 *
 *      If the driver has implemented its own hardware-based drawing function,
 *      implementing this function is highly recommended.
 */
int xxxfb_sync(struct fb_info *info)
{
	return 0;
}

    /*
     *  Frame buffer operations
     */

static struct fb_ops xxxfb_ops = {
	.owner		= THIS_MODULE,
	.fb_open	= xxxfb_open,
	.fb_read	= xxxfb_read,
	.fb_write	= xxxfb_write,
	.fb_release	= xxxfb_release,
	.fb_check_var	= xxxfb_check_var,
	.fb_set_par	= xxxfb_set_par,
	.fb_setcolreg	= xxxfb_setcolreg,
	.fb_blank	= xxxfb_blank,
	.fb_pan_display	= xxxfb_pan_display,
	.fb_fillrect	= xxxfb_fillrect, 	/* Needed !!! */
	.fb_copyarea	= xxxfb_copyarea,	/* Needed !!! */
	.fb_imageblit	= xxxfb_imageblit,	/* Needed !!! */
	.fb_cursor	= xxxfb_cursor,		/* Optional !!! */
	.fb_rotate	= xxxfb_rotate,
	.fb_sync	= xxxfb_sync,
	.fb_ioctl	= xxxfb_ioctl,
	.fb_mmap	= xxxfb_mmap,
};

/* ------------------------------------------------------------------------- */

    /*
     *  Initialization
     */

/* static int __init xxfb_probe (struct platform_device *pdev) -- for platform devs */
static int __devinit xxxfb_probe(struct pci_dev *dev,
			      const struct pci_device_id *ent)
{
    struct fb_info *info;
    struct xxx_par *par;
    struct device *device = &dev->dev; /* or &pdev->dev */
    int cmap_len, retval;	
   
    /*
     * Dynamically allocate info and par
     */
    info = framebuffer_alloc(sizeof(struct xxx_par), device);

    if (!info) {